Physics of Wave Processes and Radio SystemsPhysics of Wave Processes and Radio Systems1810-31892782-294XPovolzhskiy State University of Telecommunications and Informatics1091310.18469/1810-3189.2022.25.4.39-45Research ArticleIncreasing of bit error rate performance for OFDM systems over fading channelsAverinaLarisa I.<p>Doctor of Physical and Mathematical Sciences, professor</p>averina@phys.vsu.ruhttps://orcid.org/0000-0002-5908-5032LafickiyAlexandr Yu.<p>postgraduate student</p>unexepected@yandex.ruVoronezh State University31122022254394525122022Copyright © 2022, Averina L.I., Lafickiy A.Y.2022<p>A method for increasing performance of OFDM systems in multipath channels is proposed. The proposed method uses Kalman filter based channel estimator with block type pilot structure. Performance of the proposed method has been demonstrated for GSCM/EDGE channel models, typical for urban area and very small cells. The characteristics of the proposed algorithm are compared with other well-known methods. The impact of Doppler spread is considered. A computer simulation has been carried out to evaluate the required signal-to-noise ratio in case of fixed bit error probability. It is shown, that proposed method leads to lower bit error ratio for slow fading case, but its performance degrades with increasing Doppler frequency.</p>OFDMпомехоустойчивостьмноголучевой каналфильтр КалманаOFDMrobustnessmultipath channelKalman filter[Gusyatinskiy I.A. et al. Long Distance Tropospheric Radio. Moscow: Svyaz’, 1968, 248 p. (In Russ.)][Sklyar B. Digital Communication. Theoretical Foundations and Practical Application. Transl. from English, 2nd ed., corrected. Moscow: Vil’yams, 2003, 1104 p. (In Russ.)][Chen W., Ruifeng Z. Kalman-filter channel estimator for OFDM systems in time and frequency-selective fading environment. 2004 IEEE International Conference on Acoustics, Speech, and Signal Processing, 2004, vol. 4, pp. 377–380. DOI: https://doi.org/10.1109/ICASSP.2004.1326842][Hijazi H., Ros L. OFDM high speed channel complex gains estimation using Kalman filter and QR-detector. 2008 IEEE International Symposium on Wireless Communication Systems, 2008, pp. 26–30. DOI: https://doi.org/10.1109/ISWCS.2008.4726011][Enescu M., Roman T., Herdin M. Kalman-based estimation of measured channels in mobile MIMO-OFDM system. 2004 12th European Signal Processing Conference, 2004, pp. 1865–1868.][Diniz P.S.R. Adaptive Filtering. Algorithms and Practical Implementation. 4th edition. New York: Springer, 2013, 652 p. DOI: https://doi.org/10.1007/978-1-4614-4106-9][Kalman Filtering and Neural Networks. Ed. by S. Haykin. New York: John Wiley & Sons, Inc., 2001, 284 p. DOI: https://doi.org/10.1002/0471221546][Li Y., Cimini L.J. Interchannel interference of OFDM in mobile radio channels. Globecom ‘00 – IEEE. Global Telecommunications Conference, 2000, vol. 2, pp. 706–710. DOI: https://doi.org/10.1109/GLOCOM.2000.891231][Averina L.I., Lafickiy A.Yu. Increasing the Data Rate in Fading Links. Teoriya i tekhnika radiosvyazi, 2019, no. 4, pp. 5–10. (In Russ.)]